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Maths question vectors

The question is, find the vector equation of AB a has coordinates 5,1,2 and B has -1, 7, 8

Im kida confused because the answer has

5, 1 ,2 + lander ( 1, -1, -1) , isnt it different?

Reply 1

ombtom

Original post by SunDun111

The question is, find the vector equation of AB a has coordinates 5,1,2 and B has -1, 7, 8

Im kida confused because the answer has

5, 1 ,2 + lander ( 1, -1, -1) , isnt it different?

The vector equation of a line is:
(point the line passes through) + k*(direction of the line).

k can be another letter, often lambda.

AB passes through (5, 1, 2). The question probably said find a vector equation, not the vector equation. This is because using (-1, 7, 8) instead of (5, 1, 2) would also be acceptable.

Say the direction of a line is (12, 12, 12); you can simplify this to (1, 1, 1) – as long as the ratio is the same.

Hope this helps. :smile: